The present invention relates to quantum computing, and more specifically, to systems and methods for a low-loss planar qubit for increased coherence times.
Quantum computing employs resonant structures called qubits to store information, and resonators (e.g., as a two-dimensional (2D) planar waveguide or as a three-dimensional (3D) microwave cavity) to read out and manipulate the qubits. To date, a major focus has been on improving lifetimes of the qubits in order to allow calculations (i.e. manipulation and readout) to take place before the information is lost to decoherence of the qubits. Currently, qubit coherence times can be as high as 100 microseconds and efforts are being made to increase the coherence times. One area of research with respect to increasing coherence times is focused on eliminating material at the sharp edges of the qubit (i.e., edges) in order to reduce the electric field in that area. The material in proximity to the qubit includes imperfections that support defects known as two-level systems (TLS). Although this solution helps increase coherence times by reducing the material impact of high electric fields, the solution does not address the source and reduce the field strength.